The present invention generally relates to the field of computer animation and more particularly, is directed to a method for defining animation parameters for an animation definition interface.
In recent years, advances in personal computer hardware has made it possible to process audio and digital images on the desktop. These advances were aided by the development of sophisticated formats and standards for coding audio-visual information, such as movies, video, music and the like, in digital compressed formats. Such formats allow large amounts of audio/video data to be processed with relatively low cost equipment.
Under the direction of the International Standards Organization (ISO) and the International Electro-Technical Commission (IEC), the xe2x80x9cMoving Picture Experts Groupxe2x80x9d (xe2x80x9cMPEGxe2x80x9d) was established to development the MPEG suit of standards for coding moving pictures and audio. The major advantage of MPEG over other video and audio standards is said to be much smaller file size for the same quality due to the efficient compression techniques employed.
MPEG encoded video files are typically xe2x80x9cplayedxe2x80x9d on a PC, Mac or other consumer electronics device using an MPEG video player and MPEG audio files are xe2x80x9cplayedxe2x80x9d using an MPEG audio player. Such players are readily available to PC users and the number of MPEG encoded video and audio files is steady growing.
As the need for more demanding and varied encoding schemes for video and audio content continue to increased, MPEG has been derived into the following categories:
MPEG 1xe2x80x94Coding of moving pictures and associated audio for digital storage media at up approximately 1.5 Mbit/s;
MPEG 2xe2x80x94Generic coding of moving pictures and associated audio information; and
MPEG 4xe2x80x94Coding of audio-visual objects.
Along with the development of MPEG, real-time animation on the desk top also has gained popularity in recent years. Many real-time animation programs, including upcoming MPEG-4 terminals with face and body animation capabilities, can be used to run a proprietary renderer using a proprietary face or body model. Usually, animation of a proprietary model is not compatible with MPEG-4 requirements. Furthermore, the current implementation and modification of animation parameters, like smiles or eyebrow movement, with these renderers is cumbersome and time consuming. Thus, there is a need in the art for an improved method of processing animation parameters.
Accordingly, it is an object of the present invention to obviate the above-noted shortcomings and disadvantages of real-time animation processes known in the prior art.
Another object of the present invention is to provide an animation definition interface for an MPEG renderer which can be easily and inexpensively implemented allowing for animation of arbitrary downloaded models in the MPEG-4 terminal.
It is another object of the present invention to provide an inexpensive and easily followed method for real-time animation.
The above mentioned disadvantages of prior art real-time animation with MPEG compliant renderers can be eliminated or substantially reduced by the present invention. In accordance with the invention, a method is provided that allows the rapid definition of animation parameters for proprietary models downloaded from an MPEG-4 encoder and their inclusion into proprietary real-time rendering software that might also be MPEG-4 compliant. The proprietary model can be read into any commercially available modeler. The modeler is then used to define the behavior of different animation parameters. For each animation parameter, a modified model is created and stored. Model analysis software, known as an animation definition interface, compares the original model with the animated model and extracts the essential animation parameters which represents the differences between the original and modified models. These parameters are stored in tables and are used by the real-time animation program to generate the desired expressions.